大别山木子店地区斑状角闪黑云二长花岗岩株的锆石U-Pb年龄、Hf同位素组成及其地质意义

发布时间：2018-06-05 05:12

本文选题：斑状角闪黑云二长花岗岩 + LA-ICP-MS　；参考：《地质科技情报》2017年06期

【摘要】：大别山木子店地区岩浆岩由中生代花岗岩类和元古宙石英闪长岩、英云闪长岩组成。对中生代斑状角闪黑云二长花岗岩进行了原位LA-ICP-MS锆石U-Pb年龄和Hf同位素测定。结果表明,该花岗岩形成于(133±2)Ma,为早白垩世岩浆活动的产物。锆石εHf(t)介于-26.5~-19.6,平均值为-24.9,二阶段模式年龄T_(DM2)主要介于2 531~2 139Ma,2个继承锆石分析点分别给出了-3.0和-0.3的εHf(t)值,二阶段模式年龄T_(DM2)分别为1 589Ma和1 654Ma。上述研究表明,木子店地区斑状角闪黑云二长花岗岩为古元古代古老地壳物质部分熔融形成,形成过程中可能有新元古代地壳物质加入。综合分析认为,该花岗岩可能形成于大别造山带从挤压向伸展的转换阶段。与沙坪沟赋矿花岗岩具有类似的岩浆物质来源,指示木子店地区具有寻找早白垩世早期钼矿的可能。
[Abstract]:The magmatic rocks in Muzidian area of Dabie Mountain are composed of Mesozoic granitoids, Proterozoic quartz diorite and quartz diorite. The in situ LA-ICP-MS zircon U-Pb age and HF isotopes of the Mesozoic porphyry hornblende monzonitic granites were measured. The results show that the granite was formed at 133 卤2 Ma, which is the product of early Cretaceous magmatic activity. The zircon 蔚 Hft) ranges from -26.5 to 19.6, with an average of -24.9.The two-stage model age TX DM2) is mainly between 2531 and 2139Ma.The two inherited zircon analysis points give 蔚 Hftt values of -3.0 and -0.3, respectively, and the two-stage model age TX DM2 is 1 589Ma and 1 654 Ma. respectively. The results show that the porphyry hornblende bifeldite in Muzidian area is formed by partial melting of Gu Yuan ancient crustal materials and may be joined by Neoproterozoic crustal materials during the formation process. It is considered that the granite may have been formed during the transition from compression to extension in the Dabie orogenic belt. The source of magmatic material is similar to that of Shapinggou host granites, which indicates that the Mozidian area is likely to look for molybdenum deposits in early Cretaceous.
【作者单位】：中国地质调查局武汉地质调查中心;中国地质调查局花岗岩成岩成矿地质研究中心;
【基金】：中国地质调查局项目(1212011306800)
【分类号】：P588.121;P597

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